Octagonal-shaped diamond



FIG. 1 is a top plan view of the octagonal-shaped diamond design according to one embodiment;

FIG. 2 is a bottom plan view of the octagonal-shaped diamond design; and,

FIG. 3 is a side elevation view of the octagonal-shaped diamond design according to one embodiment. 

The ornamental design for an octagonal-shaped diamond, as shown and described. 